I blogged about these in 2022 and promised an explanation "soon". Here it is!
A fun notation for byte values:
But it looks a little nicer if you round things off:
In the usual notation, that's 03 . 24 3F 6A 88 85 A3 08 D3 and so on.
The angular form is somewhat inspired by Norse runes, especially bind runes. The round form is intended to be mistakable for as many Latin, Greek, and Cyrillic letters as possible.
I have since learned about Cistercian numerals, which are a fun medieval take on the same concept.
As usual, there's a messy notebook.